JP2014177178A - Control unit of hybrid electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control unit of a hybrid electric vehicle, which includes a dual clutch transmission, capable of suppressing oscillations which occurs at the time of starting a vehicle and derives from precharge control (preload control), and alleviating discomfort to be perceived by a driver.SOLUTION: When an engine restart condition is established (S1), if an oil temperature is larger than a predetermined temperature (S2) and an engine stop time is longer than a first predetermined time (S3), a first shortening gain and precharge delay time dependent on the engine stop time are designated (S4 and S5). If travel with a motor alone can be performed, after the delay time has elapsed (S6 and S7), precharge is executed for the shortened precharge time (S10).

Description

  The present invention relates to a hybrid electric vehicle that includes an engine and an electric motor as driving sources for traveling and has a dual clutch transmission including two transmission mechanisms as a transmission. It relates to hydraulic control technology.

  As a transmission, a so-called dual clutch transmission has been developed that has two clutches and two transmission mechanisms corresponding to the two clutches, and performs gear shifting by alternately switching the gear positions. Further, in the dual clutch transmission, there is a hybrid electric vehicle in which an electric motor is mounted on one power transmission system and an engine and an electric motor can be switched as a driving source for traveling (see Patent Document 1).

  In such a dual clutch transmission, during traveling, the clutch corresponding to one transmission mechanism used for power transmission is connected, and the other clutch in the standby state is in a disconnected state. And in such a transmission having a wet clutch, including such a dual clutch transmission, in order to switch the gear stage at an early stage, the corresponding clutch is filled with hydraulic oil in advance before shifting, so-called Precharge control (preload control) is performed (see Patent Document 2).

JP 2010-36781 A JP 2004-286183 A

  In the hybrid electric vehicle, it is possible to start with only the electric motor from the vehicle stopped state, but in the hybrid electric vehicle including the dual clutch transmission as in Patent Document 1, the precharge control as in Patent Document 2 is adopted. In this case, when starting with only the electric motor, there is a problem that vibration is generated by starting the engine and precharging the clutch corresponding to the speed change mechanism to be used next.

  This occurs particularly when the engine has been stopped for a long time, or when the temperature of the hydraulic oil supplied to the clutch is high. In other words, when the engine is stopped, the hydraulic pump is also stopped, and when the engine is started from the state where the hydraulic oil filled in the clutch is discharged to the oil pan, the hydraulic oil is vigorously supplied to the clutch, and the hydraulic pressure is excessive. The oil pressure pulsates. For this reason, the clutch is temporarily in a power transmission state, and it is considered that vibration is caused by the interference between the engine side in the idle operation state and the motor side that has started to rotate for vehicle start-up.

  In particular, this kind of vibration is a so-called idle stop / auto start function that improves fuel efficiency and exhaust gas performance by automatically stopping the engine during parking and waiting for a signal and restarting it when starting. In a hybrid electric vehicle employing an automatic stop / restart system, the engine is frequently stopped and restarted, which may occur significantly and may cause discomfort to the driver.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a hybrid electric vehicle having a dual clutch transmission at the time of vehicle start caused by precharge control (preload control). An object of the present invention is to provide a control device for a hybrid electric vehicle that can suppress vibrations and reduce discomfort to the driver.

  In order to achieve the above object, in the control apparatus for a hybrid electric vehicle according to the present invention, an engine and an electric motor as a driving source for traveling, a transmission having a first transmission mechanism and a second transmission mechanism, A first power transmission system in which the power of the engine is transmitted to the drive wheels via the first speed change mechanism, and the power of the engine and the motor is transmitted to the drive wheels via the second speed change mechanism. A second power transmission system, a first clutch provided between the engine and the transmission in the first power transmission system, and an engine and an electric motor in the second power transmission system. And a hydraulic pressure supply means for supplying hydraulic oil for generating hydraulic pressure to the first clutch and the second clutch. The above Pre-pressure control means for performing pre-load control for pre-filling the hydraulic oil before connection of the first clutch and the second clutch via the pressure supply means, and only the electric motor for starting the engine that has been stopped And a preload time control means for setting the hydraulic oil filling time in accordance with the stop time of the engine when the vehicle is started.

  Preferably, the preload time control means is set to shorten the filling time of the hydraulic oil as the engine stop time is longer. The longer the engine stop time, the greater the amount of hydraulic oil that can be removed from each clutch. By shortening the filling time, it is possible to prevent the hydraulic pressure of each clutch from becoming excessive.

  In the control apparatus for a hybrid electric vehicle according to the present invention, an engine and an electric motor as a driving source for traveling, a transmission having a first transmission mechanism and a second transmission mechanism, and the power of the engine are A first power transmission system that is transmitted to the drive wheels via one speed change mechanism, and a second power transmission that is transmitted to the drive wheels via the second speed change mechanism. A first clutch provided between the engine and the transmission in the first power transmission system, and a second clutch provided between the engine and the electric motor in the second power transmission system. A control device for a hybrid electric vehicle, comprising: a hydraulic pressure supply means for supplying hydraulic oil for generating hydraulic pressure to the first clutch and the second clutch; and the hydraulic pressure supply means. Before When preload control means for performing preload control in which the hydraulic oil is charged in advance before the first clutch and the second clutch are connected, and when the engine that has been stopped is started and the vehicle is started only by the electric motor, Preload time control means for setting the filling time of the hydraulic oil according to the temperature of the hydraulic oil supplied by the hydraulic pressure supply means.

  In this case, it is preferable that the preload time control means is set to shorten the filling time of the hydraulic oil as the temperature of the hydraulic oil increases. The higher the temperature of the hydraulic oil, the greater the amount of hydraulic oil that can be removed from each clutch, and the higher the hydraulic oil is supplied, the higher the hydraulic oil is supplied. By shortening the filling time, it is possible to prevent the hydraulic pressure of each clutch from becoming excessive.

  Preferably, the vehicle further includes gear position detecting means for detecting a gear position selected in the transmission, and the preload time control means operates according to the gear speed detected by the gear position detecting means. Oil filling time may be set. Since the torque shock when the clutch is engaged unintentionally during preload control according to the gear position, the hydraulic oil filling time is set according to the gear position so that the vehicle starts due to preload control. The driver's vibration can be suppressed to a minimum, and the driver's discomfort can be reduced.

  Furthermore, when starting the engine that has been stopped and starting the vehicle with only the electric motor, preload delay control means for delaying a start time of the preload control by the preload control means by a predetermined delay time may be provided. As a result, the preload control is performed after the rotation of the electric motor is stabilized after the engine is started, and even if the preload control temporarily causes the clutch to be in a power transmission state, the preload control causes the vibration to interfere with the rotation on the engine side. There is no need to do it.

  Preferably, the preload delay control means immediately starts the preload control by the preload control means when the vehicle cannot be started only by the electric motor within the predetermined delay time. Good. In other words, by making it possible to immediately connect the clutch when it is difficult to start the vehicle with only the electric motor, it is possible to respond quickly to acceleration requests from the driver and reduce driver discomfort. it can.

  More preferably, engine automatic stop / restart control means for stopping fuel supply to the engine when a predetermined engine automatic stop condition is satisfied and restarting the engine when a predetermined engine automatic start condition is satisfied. The engine automatic stop / restart control means starts the engine in a stopped state, and then starts the vehicle using only the electric motor. By applying the automatic stop / restart control in which the engine is frequently stopped and restarted, discomfort to the driver can be greatly reduced.

  According to the control apparatus for a hybrid electric vehicle of the present invention using the above means, in a hybrid electric vehicle having a dual clutch transmission, when the engine that has been stopped is started and the vehicle is started only by the electric motor, The hydraulic oil filling time in the preload control is set in accordance with the stop time or the hydraulic oil temperature.

If the engine stops and hydraulic oil is not supplied to each clutch, the hydraulic oil filled in each clutch will gradually escape to the oil pan. The hydraulic pressure supply state at the time of starting by changes.
In addition, since the speed at which the hydraulic oil escapes to the oil pan changes according to the temperature of the hydraulic oil, the hydraulic pressure supply state after engine startup changes according to the hydraulic oil temperature.

  Therefore, preload control suitable for the hydraulic pressure supply state can be performed by setting the hydraulic oil filling time according to the engine stop time or the hydraulic oil temperature. Thereby, the vibration at the time of vehicle start resulting from preload control can be suppressed, and the discomfort to the driver can be reduced.

It is a schematic block diagram of the control apparatus of the hybrid electric vehicle which concerns on one Embodiment of this invention. It is a flowchart which shows the precharge control routine at the time of the vehicle start which ECU of the control apparatus of the hybrid electric vehicle which concerns on one Embodiment of this invention performs. It is a map which sets a 1st shortening gain. 6 is a map for setting a precharge delay time. It is explanatory drawing about the operation | movement of the precharge according to the state at the time of vehicle start.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a control apparatus for a hybrid electric vehicle according to an embodiment of the present invention, which will be described with reference to FIG.
A vehicle 1 shown in FIG. 1 is a hybrid electric vehicle, and has a configuration in which an engine 2 and a motor 4 (electric motor), which are driving sources for traveling, are connected to a transmission mechanism unit 8 (transmission) via a clutch unit 6. Equipment. The vehicle 1 travels by transmitting the driving force from the engine 2 and the motor 4 to the left and right drive wheels 10 and 10 (for example, rear wheels) through the clutch unit 6 and the transmission mechanism unit 8.

  Specifically, the rotational driving force output from the engine 2 (hereinafter simply referred to as driving force) is input to the clutch unit 6 via the input shaft 12 and branched into two systems within the clutch unit 6. The clutch unit 6 has two clutches, a first clutch 6 a (first clutch) and a second clutch 6 b (second clutch), and drives the engine 2 branched into two systems in the clutch unit 6. One of the forces is transmitted to the input side of the first clutch 6a, and the other is transmitted to the input side of the second clutch 6b.

  Although shown in a simplified block diagram in FIG. 1, as a specific configuration of the clutch unit 6, the first clutch 6 a and the second clutch 6 b are a hydraulic pump 14 (hydraulic supply) that is driven as the engine 2 rotates. Means) is a wet multi-plate clutch that can be connected / disconnected in accordance with the hydraulic pressure of the hydraulic fluid supplied through the hydraulic paths 16a, 16b. The hydraulic pump 14 sucks hydraulic oil from an oil pan (not shown) and pumps it to the clutches 6a and 6b, and the hydraulic oil passing through the clutches 6a and 6b is discharged to the oil pan. Further, the first clutch 6a and the second clutch 6b are coaxially arranged, the first clutch 6a is disposed inside, and the second clutch 6b is disposed outside.

  The transmission mechanism unit 8 corresponds to the first clutch 6a and the second clutch 6b. The first transmission mechanism 8a (G1 in FIG. 1) (first transmission mechanism) and the second transmission mechanism 8b (G2 in FIG. 1). Two transmission mechanisms (second transmission mechanism) are provided. The output side of the first clutch 6a is connected to the input shaft of the first transmission mechanism 8a, and the output side of the second clutch 6b is connected to the input shaft of the second transmission mechanism 8b.

  The first speed change mechanism 8a has first-speed, third-speed, and fifth-speed transmission gears as forward shift speeds. The first speed change mechanism 8a also includes a reverse speed (R). The second speed change mechanism 8b corresponding to the second clutch 6b has second speed, fourth speed, and sixth speed even-numbered speed change gears as forward speeds.

  The driving force output from the first transmission mechanism 8a and the driving force output from the second transmission mechanism 8b are both transmitted to the differential device 20 via the common output shaft 18, and the left and right driving wheels 10 are transmitted. 10 is allocated. Thus, the clutch unit 6 and the transmission mechanism unit 8 constitute a so-called dual clutch transmission.

  The motor 4 is interposed between the second clutch 6b and the second transmission mechanism 8b. Although not specifically shown, the motor 4 is disposed on the outer periphery of the output shaft of the second clutch 6b. More specifically, the rotor of the motor 4 is fixed to the outer periphery of the output shaft of the second clutch 6 b, and the stator of the motor 4 is fixed to the casing of the clutch unit 6. That is, the second clutch 6b also serves as the rotating shaft of the motor 4, the rotor rotates together with the second clutch 6b inside the stator, and the drive torque and regenerative torque generated by the magnetic field generated between the rotor and the stator are the first. It is input to the two speed change mechanism 8b.

  The motor 4 is connected to a battery 22 mounted on the vehicle 1 via an inverter 24, and receives a power supply from the battery 22 to generate drive torque. The battery 22 is a secondary battery such as lithium ion or nickel metal hydride, and the inverter 24 converts the DC power from the battery 22 into AC power and supplies the motor 4 with power. On the other hand, when the vehicle is decelerated, the motor 4 functions as a generator and is regeneratively driven. That is, the motor 4 generates AC power by the driving force transmitted in reverse from the driving wheel 10, and a deceleration resistance is applied to the driving wheel 10 by the regenerative torque generated by the motor 4 at this time. The AC power is converted into DC power by the inverter 24 and then charged to the battery 22 so that the kinetic energy generated by the rotation of the drive wheels 10 is recovered as electric energy.

  When the first clutch 6 a and the second clutch 6 b are in a disconnected state, the vehicle 1 having the above configuration is configured such that only the rotation shaft of the motor 4 is connected to the drive wheels 10 and the machine via the second transmission mechanism 8 b of the transmission mechanism unit 8. Will be connected. That is, only the drive torque (hereinafter also referred to as motor torque) generated by the motor 4 is transmitted to the drive wheels 10 as the drive torque of the vehicle 1.

  On the other hand, when one of the first clutch 6a and the second clutch 6b is in the connected state, the engine 2 and the machine are connected to the drive wheels 10 and the like via the speed change mechanism corresponding to the clutch in the connected state in the speed change mechanism unit 8. Will be connected. At this time, when the torque generated by the motor 4 is set to 0 and only the engine 2 is operated, only the driving torque generated by the engine 2 (hereinafter also referred to as engine torque) becomes the driving torque of the vehicle 1. If the motor 4 is also operated with the second clutch 6 b connected, the sum of the driving torque of the motor 4 and the driving torque of the engine 2 becomes the driving torque of the vehicle 1.

As described above, the vehicle 1 includes the first power transmission system in which the power of the engine 2 is transmitted to the drive wheels 10 via the first clutch 6a and the first transmission mechanism 8a, and the power of the engine 2 and the motor 4 is the second. There are two power transmission systems of a second power transmission system that is transmitted to the drive wheels 10 via the clutch 6b and the second speed change mechanism 8b.
The vehicle 1 includes an ECU that integrally controls the engine 2, the motor 4, the clutch unit 6, the transmission mechanism unit 8, the hydraulic pump 14, and the like so as to perform various controls such as adjustment of torque distribution of the engine 2 and the motor 4. (Electronic control unit) 30 is mounted.

Specifically, the ECU 30 is connected to each control unit (not shown) such as the engine 2, the motor 4, the clutch unit 6, the transmission mechanism unit 8, the hydraulic pump 14 and the like so as to communicate with each other using a CAN (Controller Area Network). ing.
Further, the vehicle 1 is provided with a shift position sensor 32 (shift range detection means) that detects a shift position (shift range) selected with respect to the transmission mechanism unit 8 by a shift lever operation by the driver. The shift position includes a P (parking) range selected during parking, an N (neutral) range in which the gear of the speed change mechanism unit 8 is neutral, a D (drive) range selected during forward travel, and an R (reverse) selected during reverse travel. There are a range, an M (manual) range, etc., where the gear position can be manually selected. The ECU 30 is also connected to the shift position sensor 32 by CAN, and acquires the gear position information selected in the transmission mechanism unit 8 from the shift position sensor 32 and the transmission mechanism unit 8.

The ECU 30 is connected to sensors such as an accelerator sensor 34 that detects the accelerator opening and a brake sensor 36 that detects the depression of the brake. The ECU 30 acquires accelerator opening information from the accelerator sensor 34 and brake depression information from the brake sensor 36.
In addition, the ECU 30 acquires various information such as engine speed information from the engine 2, motor speed information and motor torque information from the motor 4, SOC (State Of Charge) from the battery 22, and hydraulic oil temperature information from the hydraulic pump 14. To do.

The ECU 30 configured as described above monitors the SOC of the battery 22 and the driving state of the vehicle 1, optimizes fuel consumption and exhaust gas performance, and performs an operation in accordance with the driving request of the engine 2 and motor 4. Control the clutch unit 6, the transmission mechanism unit 8, the hydraulic pump 14, and the like.
For example, the ECU 30 in the present embodiment performs so-called engine automatic stop (idle stop) control that stops the fuel supply to the engine 2 when a predetermined engine automatic stop condition is satisfied. Further, when the predetermined engine automatic start condition is satisfied after the engine 2 is automatically stopped, the ECU 30 automatically starts the engine 2 by cranking the engine 2 with a starter (not shown) and restarting fuel supply. A so-called automatic engine restart (auto start) control is performed. In this way, the ECU 30 performs so-called engine automatic stop / restart (idle stop / auto start) control (engine automatic stop / restart control means).

Here, the predetermined engine automatic stop condition is, for example, that the vehicle speed is substantially 0, the brake depression is detected, and the accelerator pedal is not depressed, that is, the accelerator opening degree is 0. Need.
On the other hand, the predetermined engine automatic restart condition is, for example, a state where the engine automatic stop condition is not satisfied, that is, when the brake pedal is released or the accelerator pedal is depressed.

  Further, the ECU 30 in the present embodiment selects the respective gear positions of the first transmission mechanism 8a and the second transmission mechanism 8b according to the driving state of the vehicle 1, and the first clutch 6a according to the transmission mechanism used for traveling. And, one of the clutches of the second clutch 6b is connected, and the hydraulic pump 14 and each of the clutches 6a and 6b are controlled so as to disconnect the other clutch. Then, the ECU 30 performs so-called precharge control (preload control means) in which hydraulic fluid is charged in advance for connection to the clutch on the connected side (preload control means).

  However, when starting the vehicle by the motor 4 after starting the engine 2 that has been stopped, the ECU 30 stops the engine 2 (engine stop time), the operating oil temperature of each clutch 6a, 6b, Executes hydraulic oil filling time (hereinafter referred to as precharge time) and precharge control in accordance with conditions such as the speed selected in the transmission mechanism unit 8, the motor state, and the required torque required for the vehicle. The timing to perform is set (preload time control means, preload delay control means).

Here, the precharge control performed when the vehicle starts by the ECU 30 will be described in detail below.
FIG. 2 is a flowchart showing a precharge control routine at the time of vehicle start executed by the ECU 30 in the present embodiment, FIG. 3 is a map for setting a first shortening gain, and FIG. 4 is a map for setting a precharge delay time. 2 will be described with reference to the flowchart of FIG. 2 while referring to FIGS. This control is executed when the engine is started.

  First, as step S1 shown in FIG. 2, the ECU 30 determines whether the engine 2 is in a stopped state and the above-described engine automatic start condition is satisfied. When the determination result is false (No), that is, when the engine is not restarted by the engine automatic stop / restart control, the routine ends. On the other hand, if the determination result is true (Yes), the process proceeds to the next step S2.

  In step S2, the ECU 30 determines whether or not the temperature of the hydraulic oil supplied to each of the clutches 6a and 6b (hereinafter also simply referred to as oil temperature) is higher than a predetermined temperature. The predetermined temperature is set to a temperature at which, for example, pulsation or the like does not occur and can smoothly flow through the hydraulic paths 16a and 16b. When the determination result is true (Yes), that is, when the oil temperature is higher than a predetermined temperature, the hydraulic oil is easily supplied to each of the clutches 6a and 6b or is supplied in a pulsating manner. If so, the process proceeds to the next step S3.

  In step S3, the ECU 30 measures the time from when the engine 2 is stopped until it is restarted, and determines whether or not the stop time of the engine 2 is longer than the first predetermined time t1. When the determination result is true (Yes), that is, when the engine 2 is stopped, the ECU 30 stops the hydraulic pump 14, and the hydraulic oil filled in the clutches 6 a and 6 b escapes to the oil pan more than a predetermined amount. If it is, the process proceeds to step S4.

In step S4, the ECU 30 sets the first shortening gain α according to the engine stop time based on the map shown in FIG.
The first shortening gain α uses a precharge time set for performing a shift operation during normal traveling according to the specifications of each vehicle as a reference time, and shortens the precharge time with respect to the reference time. For gain.

  The first shortening gain α is set lower as the engine stop time becomes longer. Specifically, as shown in the map of FIG. 3, the first shortening gain α in the present embodiment is set in two stages. That is, the first shortening gain α decreases at a constant rate from 1.0 (reference value) to the first set value a1 from the first predetermined time t1 to the second predetermined time t2, and the second predetermined time. From t2 to the third predetermined time t3, the first set value a1 is set. The first shortening gain α decreases at a constant rate from the first set value G1 to the second set value G2 from the third predetermined time t3 to the fourth predetermined time t4, and after the fourth predetermined time t4, the second set value is set. Set to the value a2. After setting the first shortening gain α based on the map, the ECU 30 proceeds to the next step S5.

In step S5, the ECU 30 sets a delay time for delaying the timing for executing the precharge control based on the map shown in FIG.
As shown in FIG. 4, the delay time is set according to the oil temperature. Specifically, the delay time is set longer as the temperature rises until the oil temperature reaches a certain temperature, and the delay time is set to a certain time above the certain temperature. After setting the delay time based on the map, the ECU 30 proceeds to the next step S6.

  In step S <b> 6, the ECU 30 determines whether traveling by only the motor 4 is possible. Specifically, when the SOC of the battery 22 is insufficient or the motor 4 is broken, for example, when the motor 4 is in a so-called fail state, the ECU 30 is required to be accelerated by a large amount of depression of the accelerator. When the required torque cannot be satisfied only by the motor torque, or when the vehicle cannot move forward by creep traveling with only the motor torque due to starting from an uphill road, it is determined that traveling with only the motor 4 is impossible. When the determination result is true (Yes), that is, when the motor 4 is normal and the required torque can be satisfied only by the motor torque, the process proceeds to the next step S7.

  In step S7, the ECU 30 determines whether or not the precharge delay time set in step S5 has elapsed since the engine 2 was started. If the delay time has not yet elapsed and the determination result is false (No), the process returns to step S6. On the other hand, when the delay time has elapsed and the determination result is true (Yes), the process proceeds to step S8. Alternatively, if the determination result in step S6 becomes false (No) before the delay time elapses, that is, if it is impossible to travel only by the motor 4, the process immediately proceeds to step S8.

  In addition, when the oil temperature is a low temperature state equal to or lower than a predetermined temperature in Step S2 and the determination result is false (No), or the engine stop time is equal to or shorter than the first predetermined time t1 in Step S3. Even if the result is false (No), the process proceeds to step S8. That is, when the oil temperature is in a relatively low temperature state below a predetermined temperature, it is difficult to supply hydraulic oil to each of the clutches 6a and 6b, and the oil pressure is less likely to pulsate. When the time is shorter than t1, the hydraulic oil remains sufficiently in each of the clutches 6a and 6b. Therefore, it is not necessary to shorten the precharge time or delay the precharge control. Therefore, the process proceeds to step S8 without setting the first shortening gain α and the precharge delay time.

  In step S8, the ECU 30 determines whether the shift range detected by the shift position sensor 32 is the D range, the M range, or the R range, and whether or not the first speed or reverse gear is selected in the transmission mechanism unit 8. Is determined. If the determination result is true (Yes), that is, if a low-speed gear stage is selected in the transmission mechanism unit 8, the process proceeds to the next step S9.

  In step S9, the ECU 30 sets the second shortening gain β according to the selected gear position. The second shortening gain β is relative to a precharge reference time, or to a value obtained by applying the first shortening gain α to the reference time when the first shortening gain α is set in step S4. This is a gain for shortening the precharge time. In the present embodiment, the second shortening gain β is set to the same value for the first speed and the reverse gear. Different values may be used for the first speed and the reverse gear.

  In subsequent step S10, the ECU 30 starts supplying hydraulic oil from the hydraulic pump 14 to the first clutch 6a and the second clutch 6b as execution of the precharge control. Here, when at least one of the first shortening gain α and the second shortening gain β is set, the hydraulic oil to each clutch 6a, 6b is applied in the precharge time to which the set shortening gain is applied. The hydraulic pump 14 and each of the clutches 6a and 6b are controlled so that the filling is finished, and the routine is finished.

Here, referring to FIG. 5, there is shown an explanatory diagram of the precharge operation according to the state at the time of starting the vehicle when the above-described control is executed. The ratio between the delay time and the precharge time shown in the figure is shown for easy understanding, and is not related to the actual ratio.
As shown in the figure, the oil temperature is equal to or lower than a predetermined temperature (No in step S2) or the engine stop time is equal to or shorter than a first predetermined time t1 (No in step S3). If it is other than the stage (R) (step S8 is No), the ECU 30 does not reduce the precharge time and delay the precharge control, and the precharge is performed at the precharge time based on the reference time immediately after the engine 2 is started. Done.

  On the other hand, the oil temperature is higher than the predetermined temperature (step S2 is Yes), the engine stop time is longer than the first predetermined time t1 (step S3 is Yes), and the gear position is other than the first speed or the R speed (step S8 is In the case of No), the ECU 30 performs the precharge by delaying the precharge start by a predetermined time and reducing the precharge time to the time when the first shortening gain α is applied to the reference time.

Further, in this case, when the running with only the motor torque becomes impossible during the precharge delay time (No in step S6), the precharge is immediately started.
When the oil temperature is equal to or lower than the predetermined temperature (No in step S2), the engine stop time is equal to or shorter than the first predetermined time (No in step S3), and the shift speed is the first speed or the reverse speed. When step S8 is Yes), the ECU 30 does not delay the precharge, but performs the precharge by reducing the precharge time to the time when the second shortening gain β is applied to the reference time.

  Further, the oil temperature is higher than a predetermined temperature (Yes in Step S2), the engine stop time is longer than the first predetermined time (Yes in Step S3), and the shift speed is the first speed or the R speed (Step S8). If YES, the ECU 30 delays the precharge, and shortens the precharge time to a value obtained by applying the first shortening gain α and the second shortening gain β with respect to the reference time.

As described above, in the hybrid electric vehicle equipped with the dual clutch transmission, the ECU 30 starts the engine 2 that has been stopped and starts the vehicle using only the motor 4. The precharge time in the precharge control is set according to the temperature.
If the engine 2 is stopped and the hydraulic oil is not supplied to the clutches 6a and 6b, the hydraulic oil filled in the clutches 6a and 6b gradually escapes to the oil pan. The hydraulic pressure supply state after the engine starts changes. Therefore, the longer the engine stop time, the more hydraulic oil is removed from the clutches 6a and 6b, and the hydraulic oil is supplied at a higher pressure level when the hydraulic oil is supplied again. By setting the first shortening gain α so as to shorten the filling time of the hydraulic oil as the time is longer, it is possible to prevent the hydraulic pressures of the clutches 6a and 6b from becoming excessive.

  Further, since the speed at which the hydraulic oil flows out to the oil pan changes according to the oil temperature, the hydraulic pressure supply state after engine startup changes according to the oil temperature. Therefore, the higher the oil temperature, the greater the amount of hydraulic oil that is released from the clutches 6a and 6b, and the ECU 30 supplies hydraulic oil at a higher pressure level when the hydraulic oil is supplied again. By increasing the precharge time as the value increases, it is possible to prevent the hydraulic pressures of the clutches 6a and 6b from becoming excessive.

Thus, by setting the precharge time according to the engine stop time and the oil temperature, precharge control suitable for the hydraulic pressure supply state can be performed. Thereby, the vibration at the time of the vehicle start resulting from precharge control can be suppressed, and the discomfort to the driver can be reduced.
Further, in low speed gears such as the first gear speed and the reverse gear, the torque shock generated when the clutches 6a and 6b are unintentionally connected in the precharge control is large. The second shortening gain β is set so as to shorten. Thereby, the vibration at the time of vehicle start resulting from precharge control can be suppressed to the minimum, and the driver's discomfort can be reduced.

  Furthermore, the ECU 30 also performs precharge delay control, so that the precharge control is performed after the rotation of the motor 4 is stabilized. Even if the preload control temporarily causes the clutch to be in a power transmission state. , It will not vibrate due to interference with the rotation on the engine 2 side. Also in this case, the vibration can be appropriately suppressed by setting a predetermined delay time for delaying the preload control according to the oil temperature.

Here, the ECU 30 promptly responds to an acceleration request from the driver by executing precharge control so that the clutches 6a and 6b can be immediately connected when the vehicle start using only the motor 4 becomes difficult. This can reduce discomfort to the driver.
Further, the ECU 30 in the present embodiment reduces the precharge time and delays the precharge control for the vehicle 1 that performs the automatic stop / restart control in which the engine 2 is frequently stopped and restarted. Discomfort to the driver can be greatly reduced.

Although the description of the embodiment of the control apparatus for a hybrid electric vehicle according to the present invention is finished above, the embodiment is not limited to the above embodiment.
For example, the predetermined engine automatic stop condition and engine automatic start condition in the above embodiment are not limited to those described above, and may be other conditions.
In the above embodiment, the precharge delay time is set based on the map of FIG. 3 in which the delay time increases as the temperature of the hydraulic oil increases. However, the delay time is set according to the temperature of the hydraulic oil. Not limited. For example, the longer the engine stop time, the longer the delay time may be set.

  In the above-described embodiment, the precharge control at the time of engine restart in the automatic stop / restart control of the engine 2 is performed by shortening the precharge time and delaying the precharge control. Is not limited to this case. For example, it may be performed immediately after the engine 2 is started by a key ON operation of the vehicle 1 by the driver.

  In the above embodiment, when the oil temperature is equal to or higher than the predetermined temperature, the first shortening gain α is set according to the engine stop time. However, the first shortening gain α is set not only in the engine stop time but also in the oil stop time. You may set according to the magnitude of temperature. In this case, the higher the temperature of the hydraulic oil, the more hydraulic oil is removed from each clutch, and the hydraulic oil is supplied at a higher pressure level when the hydraulic oil is supplied again. As the hydraulic oil filling time is shortened, the hydraulic pressures of the clutches 6a and 6b can be prevented from becoming excessive.

1 Vehicle 2 Engine 4 Motor (electric motor)
6 Clutch unit 6a First clutch (first clutch)
6b Second clutch (second clutch)
8 Transmission mechanism unit (transmission)
8a First transmission mechanism (first transmission mechanism)
8b Second transmission mechanism (second transmission mechanism)
14 Hydraulic pump (hydraulic supply means)
30 ECU (preload control means, preload time control means, preload delay control means, engine automatic stop / restart control means)

Claims (8)

An engine and an electric motor as a driving source for traveling;
A transmission having a first transmission mechanism and a second transmission mechanism;
A first power transmission system in which power of the engine is transmitted to drive wheels via the first transmission mechanism;
A second power transmission system in which power of the engine and the electric motor is transmitted to the drive wheels via the second speed change mechanism;
A first clutch provided between the engine and the transmission in the first power transmission system;
A control device for a hybrid electric vehicle comprising: a second clutch provided between the engine and the electric motor in the second power transmission system;
Hydraulic pressure supplying means for supplying hydraulic oil for generating hydraulic pressure in the first clutch and the second clutch;
Preload control means for performing preload control in which the hydraulic oil is charged in advance before connection of the first clutch and the second clutch via the hydraulic pressure supply means;
Preload time control means for setting the hydraulic oil filling time according to the stop time of the engine when starting the engine that has been stopped and starting the vehicle with only the electric motor;
A control apparatus for a hybrid electric vehicle, comprising:   2. The control apparatus for a hybrid electric vehicle according to claim 1, wherein the preload time control means sets the filling time of the hydraulic oil to be shorter as the stop time of the engine is longer. An engine and an electric motor as a driving source for traveling;
A transmission having a first transmission mechanism and a second transmission mechanism;
A first power transmission system in which power of the engine is transmitted to drive wheels via the first transmission mechanism;
A second power transmission system in which power of the engine and the electric motor is transmitted to the drive wheels via the second speed change mechanism;
A first clutch provided between the engine and the transmission in the first power transmission system;
A control device for a hybrid electric vehicle comprising: a second clutch provided between the engine and the electric motor in the second power transmission system;
Hydraulic pressure supplying means for supplying hydraulic oil for generating hydraulic pressure in the first clutch and the second clutch;
Preload control means for performing preload control in which the hydraulic oil is charged in advance before connection of the first clutch and the second clutch via the hydraulic pressure supply means;
Preload time control means for setting the hydraulic oil filling time according to the temperature of the hydraulic oil supplied by the hydraulic pressure supply means when starting the engine that has been stopped and starting the vehicle with only the electric motor;
A control apparatus for a hybrid electric vehicle, comprising:   4. The control apparatus for a hybrid electric vehicle according to claim 3, wherein the preload time control means sets the filling time of the hydraulic oil to be shorter as the temperature of the hydraulic oil is higher. And further comprising gear position detecting means for detecting a gear position selected in the transmission,
5. The hybrid electric vehicle according to claim 1, wherein the preload time control means sets the filling time of the hydraulic oil according to a shift speed detected by the shift speed detection means. 6. Control device.   And a preload delay control means for delaying a start time of the preload control by the preload control means for a predetermined delay time when starting the engine that has been stopped and starting the vehicle with only the electric motor. A control device for a hybrid electric vehicle according to any one of claims 1 to 5.   The said preload delay control means starts the preload control by the said preload control means immediately, when it becomes impossible to start a vehicle only with the said electric motor within the said predetermined delay time. The control apparatus of the hybrid electric vehicle described in 1. The engine further comprises an engine automatic stop / restart control means for stopping the fuel supply to the engine when a predetermined engine automatic stop condition is satisfied, and restarting the engine when the predetermined engine automatic start condition is satisfied,
8. The hybrid electric vehicle according to claim 1, wherein the engine automatic stop / restart control means starts the vehicle that has been in a stopped state and then starts the vehicle using only the electric motor. 9. Control device.

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